Effects of pore-forming additives on structures and properties of PVDF/Fe3+/Cu2+hollow fiber membranes

The polyvinylidene fluoride (PVDF)/Fe3+/Cu2+ hollow fiber membranes were prepared via dry-jet wet phase-inversion method to investigate the effects of pore-forming additives on structures and properties of the membranes in this study. Using polyethylene glycol (PEG) (molecular weight: 400, 6,000, and 20,000 Da), polyvinyl pyrrolidone (PVP) K30, and glyceryl alcohol as pore-forming additives respectively, the membranes were fabricated with the dope solutions of PVDF/additive/Fe3+/Cu2+ when the temperatures of bore liquid/water bath were 60/40°C. The structures and properties of the membranes were characterized by microscope, measurement of pure water permeability (PWP), bovine serum albumin (BSA) rejection ratios, dry strength test and measurement of porosity. The results suggested that these membranes were single skinned external-pressure membranes. The resultant membranes with different organic additives were born with large and long finger-like macrovoids from inner surface. PVP K30 and glycery...